The Languages which almost became CSS

Nice article even mentioning DSSSL for the LISPers here on HN.

A question regarding a CSS design decision I could never make sense of, and for which I hope I can get a sound answer here: why did CSS need to introduce its own property space and just didn't use SGML/HTML attributes for things such as line-height etc.? For a long time, there's been the dogma not to use HTML presentational attributes. But why? Attributes in SGML were exactly designed for the purpose to hold presentational properties, as shown in TFA.

("_That_, not _which_!" I shout at the screen.)